本文以《唐律疏議‧雜律一》「施機槍作坑穽」（總394條）為論述主軸，本條律文規定了違法施作機穽罪之刑罰，其旨為因打獵而危害公共安全的犯罪行為，並懲治違法布設捕獸機關而致人死傷者，以確立適當的捕獵規定與環境安全的維護。其次，釐清設置機關一事與殺傷罪之間的法律問題，如「施機槍作坑穽」與殺傷罪有關，為何《唐律》將此條列入〈雜律〉，而不是列在〈賊盜律〉？這似乎說明了唐代的立法準則，除了具有「以罪統刑」的特色之外，對於犯罪人行為的界定，也是一種分類法條的方式。再者，綜論唐代以後與本條相關的律文，分析各朝在捕獸方面的限制與更動，以綜觀本條律文的歷史發展脈絡與法律意義。最後，引用唐代判文與實例，探討捕獸與環境安全維護的關係，以及司法者在法律推理上的邏輯分析。司法者必須清楚衡量每一種不同的犯罪行為，並分辨行為人是「故意」或「誤殺傷」等情形，以作出適當的裁決。

This article analyzes the law of setting a trap in Tang Code and discusses various violations when trapping beasts. In order to ensure the safety of human habitation, Tang Dynasty used the law to punish people who caused others’ death or injury by setting traps in inappropriate environments or manners. This article clarifies the legal issues between setting beast traps and killing and injuring people. For example, why Tang Code putted this law into the section of miscellaneous laws（雜律）, rather than the law of homicide, thief or robbery（賊盜律）? It seems that the legislative guideline of Tang Dynasty had a character of the penalty crime（以罪統刑）, which defines offenders' crime by the taxonomy of behaviors. This article further compares the norm of setting traps and its variations between the Tang Code and the legal codes of other dynasties in order to observe the historical development and signification of the law. Finally, this article considers the legal connection between trapping beasts and ensuring the habitation safety. It also demonstrates judges’ legal reasonings by referring to somelegal precedents and cases. In Tang Dynasty, judges had to measure each offender’s behavior and determine whether the case is a willful murder or manslaughterso as to make an appropriate judgement.